Colors for reflective signs.

Hi there,

The ambient lighting has nothing to do with the reflective signs you're about to design.
These reflective signs reflect the lights that are pointed directly to them. Otherwise, they're as effecient as any other standard signage.

I'd suggest you to use a nice contrast to fit with where these signs are to be installed (vehicle or other) to be seen well during the day. And remember at night, only the lights pointed towards them will make your signs reflect. EX: Signage on a car door. You will only notice the reflecting property of the sign by heading YOUR car, lights on, towards the car door.

NOTE:
If you plan to install these signs on vehicle car doors, remember this. You absolutely have to wipe your surface CLEAN. With time and the vibration of the moving vehicle, the signage might slip down slightly. This might scratch the vehicle's paint.